board/common: no need to clean up rc.local or /etc/network/*

In managed NETCONF mode /etc is always based on the image's read-only
/etc with a read-writable overlay as a RAM disk.  We control the image
and know the default rc.local is empty and the interfaces file only
list the loopback interface.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/common/rootfs/lib/infix/clean-etc

@@ -3,11 +3,8 @@
 # This is an unmanaged node, leave /etc as-is
 /lib/infix/use-etc && exit 0
 
-# This is a managed node, ignore all default configuration...
-rm -f  /etc/rc.local
-rm -rf /etc/network/interfaces*
-
-#...except for some core services
+# This is a managed node, ignore all default configuration ...
+# ... except for some core services
 reserved()
 {
     for svc in clixon getty lldpd nginx sysklogd; do